Finding the location of a person is becoming increasingly more accessible through the pervasive use of mobile devices. A reliable proxy for an individual's location is that of a device (mobile or fixed) that is associated with the individual or that can detect the presence of the individual. Examples of such devices include a user's mobile device, a user's workstation, a key card reader that a user swipes, etc. Existing location systems are generally geared towards creating a social network of individuals that give each other access to location data. The actual calculation of location data, storage of location data preferences, and the security of a user's location data remains the responsibility of each of these disparate services. Each of these services typically requests permission before accessing or sharing the user's location data. As the number of services that rely on a user's location data increases, the burden on the user to grant permission (or not) to these various services becomes substantial.
Further, many services run as applications on a mobile device. Even with improving processing power, battery life, and system architectures, mobile devices are not suited for certain types of location-based services, such as person-to-person proximity services. This problem is amplified when the number of proximity subscriptions (e.g., the number of people for whom an individual wants to be notified when proximate) increases.